In prior art, when a base station, which serves a user equipment (user equipment, UE for short), is not suitable for servicing it, the UE will be handed over to another base station. In the prior art, the process is achieved by a following manner.
A source base station (for example, an evolved NodeB (evolved NodeB, eNB for short)) sends a handover request (Handover Request) message to a target eNB.
If the handover is accepted, the target eNB points out, in a handover request acknowledge (Handover Request ACK) message, a tunnel endpoint (GPRS (general packet radio service, General Packet Radio Service) tunneling protocol (GPRS Tunneling Protocol, GTP for short) Tunnel Endpoint) where forwarding data is expected to be received. The GTP tunnel endpoint includes a transport layer address (Transport Layer Address) and a GTP TEID (Tunnel Endpoint Identifier, Tunnel Endpoint ID).
After receiving the Handover Request ACK message, a soruce eNB indicates that the UE hands over from the soruce eNB to the target eNB.
The inventor found that, in the prior art, a handover flow can merely hand over a UE from one cell to another cell, and a handover could not performed when there exists more than one source cell or target cell.